The valuable document identifying system based on the point triggering strategy in the prior art takes use of triggers to start data collection and valuable document identification. The principle of triggering is shown in FIG. 1. Photoelectric thru-beam sensors are arranged at the front end and rear end of the identifying device as position detector and are used as the triggering means for “START” and “END”. The identifying system based on point triggering strategy is shown in FIG. 2. As for the present valuable document which is separated through separating operation, it is processed with the following procedures in the system:
(1) The present valuable document enters the transmission device (not shown), and the transmission device transmits the valuable document to the effective detecting region of the position detector (not shown);
(2) The presence of the valuable document is detected by the position detector when the photoelectric thru-beam sensor (not shown) is sheltered by the valuable document; the triggering signal of “the valuable document arriving” is sent to the central controller (not shown), the central controller gives “START” instruction to start the system and informs the front end counter to count up by one;
(3) The central controller gives an instruction to start the collecting device; the collecting device starts to collect the information of the valuable document and store the collected information of the valuable document in real-time; the collecting device stops collecting after the preset collecting time T which is in connection with physical size of the valuable document, and the collecting device gives “collection END signal” to inform the central controller;
(4) The central controller informs the identifying device, and the collected information of the valuable document is processed for identification;
(5) Identification is finished, and the present valuable document is transmitted to the rear position detector; when the photoelectric thru-beam sensor is sheltered by the valuable document, the signal of “the valuable document leaving” is sent to the central controller, and the central controller informs the rear end counter to count up by one;
(6) The central controller matches the counting result of the front end counter with that of the rear end counter. If the counting results are identical, it means that the process on the present valuable document is over, and the procedure for the next piece of the valuable document starts; otherwise, the system will report an error and stop operating.
The identifying system which adopts point triggering strategy has the following deficiencies:
(1) It is likely to occur a false triggering.
Based on point triggering strategy, the signal of whether the thru-beam sensor is sheltered or not is taken as the controlling input of the system. The information from several “points” is utilized to trigger the collecting, identifying and ending operation of the system. However, when processing some valuable documents having special shape, such as having transparent holes, if the detecting point of the thru-beam sensor is located on the positions of the transparent holes of the valuable document, the thru-beam sensor will fail in the range of the transparent holes of the valuable document. Therefore, it is likely to occur a false triggering and error rate of the system will be increased.
(2) The information is not collected completely, and the identification rate is low.
When processing some valuable documents having special shape, such as having transparent holes, if the detecting point of the thru-beam sensor is located on the positions of the transparent holes of the valuable document, the beam sensor will fail in the range of the transparent holes of the valuable document. In this case, the start of the collecting and identifying operation of the system will be delayed, and the end of the system will be ahead of the schedule to stop collecting, such that the information of the valuable document is not collected completely. Therefore, the identification of the system to the valuable document is affected and the identification rate of the system is reduced.
(3) Fixed collecting time lowers down the adaptability of the system for various valuable documents.
The collecting time T of the identifying system which adopts point triggering strategy depends on the physical size and moving status of the valuable document as well as the real-time electric transmitting status of the identifying device. In practical application, various valuable documents are of different physical sizes and are subjected to the problems like movement distortion. Therefore, it is difficult to set a collecting time T which is uniform, rational and adaptable for various valuable documents, which lowers down the applicability of the valuable document identifying system and impairs the prevailing application of the identifying system.
(4) Partially adhered valuable documents cannot be counted accurately.
In the case that the adhered valuable documents pass through the identifying device, two valuable documents are completely overlapped at the moment when they pass the front end position detector. After the adhered two valuable documents have moved for a period of time, and when they passed the collecting device and the identifying device and reached the rear end position detector, the two valuable documents become partially overlapped and are not separated completely, thus they are regarded as one valuable document by the rear end counter. Therefore, the adhered notes are counted by error.